JP2007101300A - Method, device, and program for inspecting wood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately inspect wood with an image having no distortion. <P>SOLUTION: Lighting means 5 and 6 light the wood 9, a plurality of photographing means 8a, 8b and 8c photograph the wood 9 to cause overlap by a desired width, and marker means 12a and 12b radiate a mark of a narrow light beam to a substantially central part in the overlapped photograph region. An image processing means detects a shift amount of the mark position of the images photographed by the photographing means 8a, 8b and 8c from the mark position of reference wood of no distortion, corrects the images photographed by the photographing means 8a, 8b and 8c so as to eliminate the detected shift amount, composites the corrected images photographed by the plurality of photographing means 8a, 8b and 8c, and inspects the wood. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection method and apparatus for cracks and holes in a wood material such as a veneer cut out from a log of wood or the like. For example, in order to manufacture plywood, a log is cut with a blade to obtain a single plate having a thickness of several millimeters, the single plate is made to a predetermined size and dried, and then a plurality of single plates are bonded. It is integrated by bonding with an agent. In these manufacturing processes, depending on the degree of distortion (warp: blown) of the veneer, where the nodes on the veneer fell out and became holes, cracks, dislocations such as mold and discoloration, the number, area, etc. Sorted into one that forms the surface layer when it becomes plywood (aesthetically less flaws) and one that forms the inner layer of plywood (even if there are many defects) (for example, in 5-7 stages) Need to be sorted).

  Conventionally, in order to sort into the one constituting the surface layer when it becomes a plywood and the one constituting the inner layer of the plywood, the single plate conveyed by the conveyor is determined by the operator's naked eye.

Conventionally, the surface flaws of a steel sheet, which is a wide article, are used as detection means, and a plurality of line sensors and a distance sensor to the steel sheet are used. There was what was synthesized (coupled) (see Patent Document 1).
JP 2000-349988 A

  The conventional device has the following problems.

  In the determination with the naked eye, there are problems that the determination varies from person to person (inaccuracy) and the speed of the conveyor cannot be increased (productivity is poor).

  In addition, the conventional overlapping range detection means for synthesizing the captured images of each line sensor using a distance sensor requires a distance sensor separately from the line sensor and calculates the overlapping range between adjacent line sensors. Therefore, there is a problem that the equipment cost is generally increased. Also, for example, when the inspection surface is non-planar, such as when inspecting veneer veneers with flare and undulations, the calculation overlap range calculated by the conventional overlap range detection means and the actual overlap There was an error in the range.

  The present invention solves such a conventional problem, photographs wood with a plurality of photographing means, corrects distortion of the image due to blown or wavy wood from the photographed images, and photographs with a plurality of photographing means. An object of the present invention is to combine the obtained images and to obtain the size (flatness) of the waviness of the wood.

  FIG. 2 is an explanatory diagram of the image processing apparatus. In FIG. 2, 5 is a light source for transmitted light (illuminating means), 6 is a light source for reflected light (illuminating means), 8a, 8b and 8c are line sensor cameras (imaging means), 9 is a single plate (wood), 11a, 11b and 11c are camera image acquisition bases, 12a and 12b are laser markers (marker means), 13a and 13b are laser drivers, and 14 is a main computer. Here, the camera image acquisition bases 11a, 11b, and 11c and the main computer 14 are image processing means.

  The present invention is configured as follows to solve the above problems.

  (1): The illuminating means 5 and 6 illuminate the wood 9, the plurality of photographing means 8 a, 8 b, 8 c photograph the wood 9 so as to overlap the desired width, and the marker means 12 a, 12 b perform the duplication A mark of a thin light beam is applied to a substantially central portion in the photographing area to be used, and from the mark position of the image photographed by the photographing means 8a, 8b, 8c by the image processing means, The image taken by the photographing means 8a, 8b, 8c is corrected so that the detected deviation amount disappears, and the corrected images from the plurality of photographing means 8a, 8b, 8c are synthesized. Then, the wood is inspected. For this reason, it is possible to accurately inspect wood with an image having no distortion.

  (2): The illuminating means 5 and 6 illuminate the wood 9, the plurality of photographing means 8a, 8b and 8c photograph the wood 9 so as to overlap the desired width, and the marker means 12a and 12b perform the overlapping. A mark of a thin light beam is applied to a substantially central portion in the photographing area to be used, and from the mark position of the image photographed by the photographing means 8a, 8b, 8c by the image processing means, Is detected, and a distortion height, which is a distortion in the height direction of the wood, is detected from the detected deviation amount. For this reason, the grade of the wood can be selected based on the play value (quantity) which is the height of distortion of the wood.

  (3): In the method and apparatus for inspecting wood of (1) or (2), the thin light beam emitted by the marker means 12a, 12b uses a color different from the illumination of the illumination means 5, 6. For this reason, it is possible to easily detect the mark.

  (4): In the wood inspection method and apparatus of (1) to (3), the amount of deviation of the mark position is detected using the one with the maximum frequency position among a plurality of lines for detecting the mark. For this reason, an error does not occur even if the mark cannot be detected on some lines, so that a detection error can be prevented.

  The present invention has the following effects.

  (1): The image processing means detects the amount of deviation from the mark position of the reference wood without distortion from the mark positions of the images taken by the plurality of photographing means, and the photographing is performed so that the detected deviation amount disappears. The image captured by the means is corrected, and the corrected images from the plurality of image capturing means are combined to inspect the wood, so that the inspection of the wood can be performed accurately with an image without distortion.

  (2): The amount of deviation from the mark position of the reference wood without distortion is detected from the mark position of the image photographed by the photographing means by the image processing means, and the height of the wood is detected from the detected deviation amount. In order to detect the strain height, which is a strain, it is possible to select the grade of the wood based on the play value (amount) which is the strain height of the wood.

  (3): The thin light beam irradiated by the marker means uses a color different from the illumination of the illumination means, so that the mark can be easily detected.

  (4): Detection of misalignment of the mark position uses the one with the highest frequency position among the multiple lines that detect the mark, so no error occurs even if the mark cannot be detected on some lines, thus preventing detection errors can do.

(1): Description of Single Plate Sorting Device FIG. 1 is an explanatory diagram of a single plate sorting device. FIG. 1 shows the overall configuration of a single plate sorting apparatus, which includes an image processing device 1, a sorter control device 2, an operation panel 3, a belt conveyor 4, a transmitted light illumination 5, and reflected light. Lighting 6, a distribution device 7 according to grade, and a line sensor camera 8 are provided.

  The image processing apparatus 1 is an image processing unit that processes image data from the line sensor camera 8 and outputs a processing result such as a single plate quality grade to the sorter control apparatus 2. The sorter control device 2 outputs the output of the sorter conveyor control signal such as the operation and stop of the conveyor and the control signal of the graded distribution device 7 according to the output of the image processing device 1. The operation panel 3 is an operation panel for performing operations such as changing the set value of the image processing apparatus 1 and controlling the sorter control apparatus 2. The belt conveyor 4 is a conveying means for conveying the single plate 9. The transmitted light illumination 5 is an illumination means (light source) such as an LED for detecting holes, cracks, and the like of the single plate 9, and uses illumination of a color different from the reflected light illumination 6 (for example, green illumination). This is for distinguishing from the reflected light from the reflected light illumination 6 (by color and intensity) to detect a single plate hole (node hole), crack or the like. The reflected light illumination 6 is an illumination means (light source) such as an LED for detecting the reflected light of the single plate 9, and normally uses white illumination. The line sensor camera 8 is a photographing unit that photographs a line image of the single plate 9.

  In the operation of this single plate sorting device, the single plate 9 sent by the belt conveyor 4 is photographed by the line sensor camera 8 and the image data is output to the image processing device 1. The image processing apparatus 1 processes this image data, and outputs the processing results such as the veneer quality grade to the sorter control apparatus 2. The sorter control device 2 outputs a control signal to the grade distribution device 7 to sort the single plate 9 by grade. This selection includes the number of worm holes, the number of holes / missing nodes, the number of live nodes, the number of dead nodes, the number of cracks, the number of cracks, the number of spears / penetration, the blue variable, the distortion (abalone value), etc. ) Etc.

(2): Description of Image Processing Device FIG. 2 is an explanatory diagram of the image processing device. In FIG. 2, the image processing apparatus is provided with three line sensor cameras 8a, 8b, 8c, camera image acquisition bases 11a, 11b, 11c, laser markers 12a, 12b, laser drivers 13a, 13b, and a main computer 14. It is.

  The line sensor cameras 8a, 8b, and 8c are photographing means for photographing the single plate 9 by dividing it into three in a direction orthogonal to the transport direction by three cameras. The camera image acquisition platforms 11a, 11b, and 11c perform digitization processing and distribute image data to the main computer 14 each time one line image from each line sensor camera is captured. The laser markers 12a and 12b irradiate thin light beams in the conveyance direction of a single plate that is a mark for combining (combining) the images from the line sensor cameras 8a, 8b, and 8c. This irradiating light beam can be irradiated with a thin light beam (for example, a red laser monochromatic light beam) having a color different from the color of the single plate (wood) so that it can be easily removed in a later process. The laser drivers 13a and 13b are connected to an AC power source and drive the laser markers 12a and 12b. The main computer 14 includes processing means, storage means, output means, and the like, and performs image processing (image synthesis, node search, defect search processing, etc.) of the single plate 9.

  The operation of the image processing apparatus is to illuminate the conveyed single plate 9 with light beams from the transmitted light source 5 and the reflected light source 6, and use the camera image acquisition boards 11a, 11b, and 11c to perform the line sensor camera 8a, The data is distributed to the main computer 14 every time one line image is captured from 8b and 8c. The main computer 14 corrects the received image, detects an exposure value, and sequentially combines the images. Finally, when the camera image acquisition boards 11a, 11b, and 11c finish capturing the image, In the main computer 14, the synthesis of the color image and the black-and-white gray image conversion are almost completed (the images from the camera image acquisition boards 11a, 11b, and 11c in which the single-plate image is divided into three are displayed in the main computer 14. Join).

  Here, the single plate 9 is irradiated with the laser mark from the laser markers 12a and 12b and divided into three parts, and the line sensor cameras 8a, 8b and 8c are adapted to match the line images up to the respective laser marks, so that the image can be easily obtained. Allow binding. In order to improve the processing speed of the image, the node searching process can be performed with a black and white image with a large number of pixels, and the color image for searching for a dead node can be performed with a reduced image (with a small number of pixels).

  Hereinafter, the operation of the image processing apparatus will be described separately for processing during shooting and processing after shooting.

<Description of processing during shooting>
Image data photographed by the line sensor cameras 8a, 8b, and 8c is distributed to the main computer 14 for each line, and is synthesized as one whole image.

Processing of camera image acquisition bases 11a, 11b, and 11c One line color image is taken from the line sensor cameras 8a, 8b, and 8c, and the position (bonding position) of the laser mark is detected. Transfer to the main computer 14.

Processing of the main computer 14 The one-line color image that has arrived is corrected and an exposure value is detected and synthesized based on the position information (laser mark). This is because the main computer 14 completes the synthesis of the whole color image at the stage where the photographing is finished by the camera image acquisition boards 11a, 11b, and 11c and the last one-line color image is received. Further, in order to effectively use the time during shooting, processing that can be performed for each line, such as black and white conversion and reduction processing, can be performed in parallel.

<Description of processing during image analysis after shooting>
Processing of camera image acquisition boards 11a, 11b, 11c Wait until the arrival of the next board (single board) is detected.

・ Processing of the main computer 14 Based on the predetermined information such as the size and type of the target board, the node search process and the defect detection process using transmitted light are performed according to the area to be calculated and the set value, and finally the detection value is included. Perform the classification process. The result is displayed on a display device (not shown) and the result is output to the sorter control device 2.

  In the above description, the camera image acquisition bases 11a, 11b, 11c, the main computer 14 and the like in the image processing apparatus are described as using computers (PCs). However, the number of computers used is the amount of image data. Or the processing speed of the computer or the like (can be processed by one computer).

  In addition, although three line sensor cameras have been described, two or four or more line sensor cameras can be used depending on the size and type of the target board and the processing performance of the computer.

(3): Explanation of image composition by laser marker FIG. 3 is an explanatory diagram of a method for combining images. In FIG. 3, the line sensor cameras 8a, 8b, 8c have camera boxes, and the camera boxes are provided with camera lenses 21a, 21b, 21c and line sensors 22a, 22b, 22c, respectively.

  The single plate 9 is photographed by the three line sensor cameras 8a, 8b, and 8c. At this time, a mark (laser mark) is put on the middle boundary line of each camera by the laser markers 12a and 12b. If the single plate 9 is always flat, the marks of the laser markers 12a and 12b are always at the fixed positions of the line sensors 22a, 22b and 22c (indicated by dotted arrows in FIG. 3). Therefore, if the line images are joined so that the marks are aligned, the images can be easily combined.

  However, as will be described below, the veneer 9 is not always flat and may have distortion, and the distortion portion moves upward on the belt conveyor. Therefore, the marks of the laser markers 12a and 12b move outward with respect to the line sensors 22a, 22b and 22c. That is, the image appears to be enlarged on both sides with respect to the center of the sensor.

  Therefore, when images are joined, it is necessary to correct the reduction. The regular laser mark position is obtained by assuming a flat single plate, and can be corrected by the amount of deviation from it.

  FIG. 4 is an explanatory diagram of an imaging region when a flat plate is viewed from directly above. In FIG. 4, two laser marks (straight lines) are put on a flat wood board by a laser marker. The position of the laser mark on the flat wood plate becomes the position of the reference laser mark. The shooting areas of the camera 1, the camera 2, and the camera 3 are shown from the left side. The shooting area of the camera 1 (corresponding to the line sensor camera 8a) is shot to a position beyond the laser mark on the left side. The shooting area of the camera 2 (corresponding to the line sensor camera 8b) is shot up to a position exceeding the left and right laser marks. The camera 3 (corresponding to the line sensor camera 8c) captures images up to a position beyond the right laser mark. Therefore, when photographing with each camera, an overlapping area is formed with the laser mark interposed therebetween. Note that the vertical line in the center of the shooting area of each camera indicates the camera center.

  FIG. 5 is an explanatory diagram of each image when the exposed board is photographed by three cameras. In FIG. 5, the place where the amount of exposure of the wood board is large appears to expand in the horizontal direction around the center of the camera. For this reason, a straight laser mark line is bent and photographed as indicated by a thick solid line. As shown on the right side of FIG. 5, the amount of exposure can be obtained by an amount that is horizontally expanded from the position of the reference laser mark. In FIG. 5, the overlapping area is indicated by shading.

  FIG. 6 is an explanatory diagram of an image after correction of blur. In FIG. 6, when the laser mark line (thick solid line) is corrected so as to be straight, both ends of the plate also have an actual shape, and the dimensions can be obtained with high accuracy.

  FIG. 7 is an explanatory diagram of image composition. In FIG. 7, adjacent images are synthesized based on the laser mark. As a result, an entire image of the wood board subjected to the correction of the blow is obtained.

  FIG. 8 is an explanatory diagram of the image composition of the overlapping area. In FIG. 8, two images to be combined are g1 (x) and g2 (x), and the coupling ratio is β. At this time, in the overlapping region, the combined image is G (x) with respect to the two images g1 (x) and g2 (x).

Composite image G (x) = β (x) × g1 (x) + (1.0−β (x)) × g2 (x)
(X is the distance from the start point of the overlapping area, where 0 ≦ β (x) ≦ 1.0)
As a result, the images can be combined without any joints.

  Further, in the combined image, the laser mark can be removed by performing a predetermined correction process (a process of subtracting the irradiation light beam corresponding to the laser mark).

(4): Description of specific example of image correction An error is likely to occur when the position of a laser pointer (laser mark) is obtained for each image line. Therefore, the position of the laser pointer obtained for each line image is integrated by about 10 lines, and the maximum frequency position is set as the laser pointer position in the line section.

  FIG. 9 is an explanatory diagram of the laser pointer position. In FIG. 9, the maximum frequency position in every 10 rows from the top is defined as laser pointer positions Lpx (0), Lpx (1), Lpx (2),... (Indicated by white circles). For example, when the position Lpx (0) of the laser pointer is obtained, the maximum frequency position having a frequency of 5 in 10 rows is set (see “maximum frequency” in the upper part of FIG. 9).

When the reference position of the laser mark from the camera center is Lp, the position of the laser mark is Lpx, and the difference from the reference position Lp of the laser mark is d (n),
d (n) = Lpx (n) −Lp
This d (n) is obtained and calculation for height detection is performed. Further, using the laser mark reference position Lp and the laser mark position Lpx, image distortion correction is performed (the image is reduced so that the laser mark detection position is at the laser mark reference position).

(Explanation of how to correct images)
Assuming that a pixel existing at a distance (number of pixels) x from the camera center in line y is g (x, y) and a normal image after correction processing is f (x ′, y),
g (x, y) ⇒ f (x ', y)
x ′ = (Lp / Lpx) x
A regular image f is obtained as follows.

  With this conversion, the laser mark is corrected to be straight (to be at the reference position). At this time, assuming that the amount of exposure of a specific line is substantially uniform in the line direction, correction processing is performed, and the relationship between x and the reduction ratio in a specific line is as shown in FIG. Become.

  FIG. 10 is an explanatory diagram of image correction. In FIG. 10, the reduction ratio is continuously increased as the distance from the camera center to the laser mark is not reduced as shown in the lower side of FIG. By this correction, the laser mark position comes to the reference laser mark position Lp. The right side of FIG. 10 shows the amount of exposure on the plate surface.

(Explanation based on flowchart)
FIG. 11 is a process flowchart for obtaining laser mark coordinates. Hereinafter, a description will be given according to the processes S1 to S7 of FIG.

  S1: The image processing apparatus 1 obtains an image of one line from the line sensor camera, and proceeds to processing S2.

  S2: The image processing apparatus 1 obtains the laser mark position Lpx in one line, and proceeds to processing S3.

  S3: The image processing apparatus 1 increases (+1) the value of the coordinate P [Lpx], and proceeds to processing S4.

  S4: The image processing apparatus 1 determines whether the required number of rows has been reached. If it is determined that the required number of rows has been reached, the process proceeds to step S5. If not, the process returns to step S1.

  S5: The image processing apparatus 1 obtains the most frequent position of the counter P [x] of the laser mark position = Lpx (n) (that is, obtains the laser mark position having the highest appearance frequency in the number of acquired rows, and calculates it. Lpx (n)). The obtained Lpx (n) is stored as storage data in the storage means, and the process proceeds to step S6.

  S6: The image processing apparatus 1 determines whether the final number of rows has been reached. If it is determined that the final number of rows has been reached, the process proceeds to step S7. If not, the process returns to step S1.

  S7: The image processing apparatus 1 uses the approximate curve for Lpx (0) to Lpx (n) obtained in each row section as the mark line in the entire image, and obtains the difference from the reference position (laser reference) of the laser mark. The process proceeds to (image correction, processing for obtaining flatness (blurring value), etc.).

(5): Description of height detection The veneer is not necessarily flat and has distortion, and the distortion part moves upward on the belt conveyor. Therefore, the mark of the laser marker moves outward with respect to the line sensor. Therefore, the image appears to be enlarged on both sides with respect to the center of the sensor (camera center). In addition, since the regular laser mark position can be obtained by assuming a flat single plate, the amount of deviation can be known. Since the amount of this deviation is proportional to the upward movement value of the laser mark, that is, the deviation value of the single plate, it can be used for examining the flatness of the single plate.

  FIG. 12 is an explanatory diagram of height detection of a single plate. In FIG. 12, the distance from the camera center of the line sensor camera on the single plate to the laser mark in the horizontal direction is Lm, the height of the distorted single plate from the flat single plate (distortion height) is Dh, and the flat single The height from the plate to the lens 21 is H, the distance (pixel) from the sensor center on the sensor 22 to the regular laser mark position is Lp, and the single plate on the sensor 22 is distorted. The amount (pixel) is d, and the distortion height dh obtained on the sensor 22 is set.

Here, the relationship between the shift amount d and the distortion height Dh is:
Since Dh / dh = Lm / Lp and dh / d≈H / Lm, Dh≈ (H / Lp) × d
It becomes. Thus, the distortion height Dh (the distance H from the flat single plate to the lens 21 and the distance from the regular laser mark position (pixel) Lp is a fixed value) from the deviation amount (pixel) d on the sensor 22 Desired.

(6): Explanation of image composition and height detection FIG. 13 is an explanatory diagram of image composition and height detection processing. Hereinafter, a description will be given according to processing S11 to S43 of FIG.

  S11: The image processing apparatus 1 acquires an image of one line from the line sensor camera 1, and proceeds to processing S12.

  S12: The image processing apparatus 1 integrates images of several lines (10 lines in the example of FIG. 9), detects the laser mark position from the maximum frequency position of the laser mark, and proceeds to processing S13 and processing S41.

  S13: The image processing apparatus 1 corrects distortion in the line direction of the image (correctly corrects the side where the laser mark is not detected), and proceeds to processing S43.

  S21: The image processing apparatus 1 acquires an image of one line from the line sensor camera 2, and proceeds to processing S22.

  S22: The image processing apparatus 1 integrates images of several lines (10 lines in the example of FIG. 9), detects the laser mark position from the maximum frequency position of the laser mark, and proceeds to processing S23 and processing S41 and S42.

  S23: The image processing apparatus 1 corrects the distortion in the line direction of the image based on the detected left and right laser mark positions, and proceeds to processing S43.

  S31: The image processing apparatus 1 acquires an image of one line from the line sensor camera 3, and proceeds to processing S32.

  S32: The image processing apparatus 1 integrates the images of several lines (10 lines in the example of FIG. 9), detects the laser mark position from the maximum frequency position of the laser mark, and proceeds to processing S33 and processing S42.

  S33: The image processing apparatus 1 corrects distortion in the line direction of the image (correctly corrects the side where the laser mark is not detected), and proceeds to processing S43.

  S41: The image processing apparatus 1 obtains an average of the positional deviations on both sides (cameras 1 and 2) of the laser mark and converts it to a height (height detection process).

  S42: The image processing apparatus 1 obtains an average of positional deviations on both sides (cameras 2 and 3) of the laser mark and converts it to a height (height detection process).

  S43: The image processing apparatus 1 combines the images of the three cameras based on the reference position of the laser mark (image combining process).

  As described above, it is possible to select the grade of the single plate by detecting the height of the distortion of the single plate (the amount of play) based on the average or total of the heights detected in the processes S41 and S42. Further, the number of live nodes, number of dead nodes, number of cracks, number of cracks, number of worm holes, number of holes / missing joints, number of spears / penetration, blue variables, etc., and the size of these by the image synthesized in step S43 Etc. can be detected and the grade of the single plate can be selected.

(10): Description of program installation The image processing device (image processing means) 1, the sorter control device (sorter control means) 2, the camera image acquisition bases 11a, 11b, 11c, the main computer 14, etc. are configured by programs. It can be executed by the main control unit (CPU) and is stored in the main memory. This program is processed by a computer. The computer includes hardware such as a main control unit, main memory, a file device, an output device such as a display device, and an input device.

  The program of the present invention is installed on this computer. In this installation, these programs are stored in a portable recording (storage) medium such as a floppy disk or a magneto-optical disk, and a drive device for accessing the recording medium provided in the computer is used. Alternatively, it is installed in a file device provided in the computer via a network such as a LAN. Accordingly, it is possible to easily provide a wood inspection apparatus capable of correcting a distortion of a photographed image to obtain an accurate image of the wood, inspecting the wood, and detecting a height of the wood distortion (amount of play). it can.

It is explanatory drawing of the single-plate sorting apparatus of this invention. It is explanatory drawing of the image processing apparatus of this invention. It is explanatory drawing of the combining method of the image of this invention. It is explanatory drawing of an imaging | photography area | region when seeing the flat board of this invention from right above. It is explanatory drawing of each image when image | photographing the exposed board of this invention with three cameras. It is explanatory drawing of the image after the blur correction of this invention. It is explanatory drawing of the synthesis | combination of the image of this invention. It is explanatory drawing of the image composition of the overlap area | region of this invention. It is explanatory drawing of the laser pointer position of this invention. It is explanatory drawing of the correction | amendment of the image of this invention. It is a processing flowchart for obtaining the laser mark coordinates of the present invention. It is explanatory drawing of the height detection of the single board of this invention. It is explanatory drawing of the image composition and height detection process of this invention.

Explanation of symbols

5 Light source for transmitted light (illumination means)
6 Light source for reflected light (illumination means)
8a, 8b, 8c Line sensor camera (photographing means)
9 Single board (wood)
11a, 11b, 11c Camera image acquisition base 12a, 12b Laser marker (marker means)
13a, 13b Laser driver 14 Main computer

Claims (10)

Lighting the wood with lighting means,
Take a picture of the wood so as to overlap the desired width with a plurality of photography means,
Irradiate a mark of a thin light beam to the substantially central part in the imaging area to be overlapped by the marker means,
The image processing means detects the amount of deviation from the mark position of the reference wood without distortion from the mark position of the image photographed by the photographing means, and the photographing means takes a picture so that the detected deviation amount disappears. A method for inspecting wood, comprising correcting an image and combining the images from the plurality of photographing means thus corrected to inspect the wood. Lighting the wood with lighting means,
Take a picture of the wood so as to overlap the desired width with a plurality of photography means,
Irradiate a mark of a thin light beam to the substantially central part in the imaging area to be overlapped by the marker means,
The image processing means detects a deviation amount from the mark position of the reference wood without distortion from the mark position of the image photographed by the photographing means, and is a distortion in the height direction of the wood from the detected deviation amount. A method for inspecting wood characterized by detecting strain height. 3. The method for inspecting wood according to claim 1, wherein the thin light beam emitted by the marker means uses a color different from the illumination of the illumination means. The method for inspecting wood according to any one of claims 1 to 3, wherein the deviation of the mark position is detected by using the one with the highest frequency position among a plurality of lines for detecting the mark. Lighting means for lighting the wood;
A plurality of photographing means for photographing the wood so as to overlap the desired width;
Marker means for irradiating a mark of a thin light beam at a substantially central portion in the overlapping photographing area;
From the mark position of the image photographed by the photographing means, an amount of deviation from a reference wood mark position without distortion is detected, and the image photographed by the photographing means is corrected so as to eliminate the detected deviation amount. And an image processing means for inspecting the wood by combining the corrected images from the plurality of photographing means. Lighting means for lighting the wood;
A plurality of photographing means for photographing the wood so as to overlap the desired width;
Marker means for irradiating a mark of a thin light beam at a substantially central portion in the overlapping photographing area;
From the mark position of the image photographed by the photographing means, a deviation amount from a reference wood mark position without distortion is detected, and a distortion height which is a distortion in the height direction of the wood is detected from the detected deviation amount. An inspection apparatus for wood comprising an image processing means for detection. The wood inspection apparatus according to claim 5 or 6, wherein the thin light beam emitted by the marker means uses a color different from the illumination of the illumination means. The detection of the amount of deviation of the mark position by the image processing means uses the one with the highest frequency position among a plurality of lines for detecting the mark. Inspection device. From the mark position of the image taken by the plurality of photographing means for photographing the wood in which the thin light beam mark is irradiated at the substantially central portion in the photographing area to be photographed with the desired width overlapping, the reference wood having no distortion is obtained. The amount of deviation from the mark position is detected, the image photographed by the photographing means is corrected so that the detected deviation amount disappears, and the corrected images from the plurality of photographing means are combined to inspect the wood. A program for causing a computer to function as image processing means to be performed. From the mark position of the image taken by the plurality of photographing means for photographing the wood in which the thin light beam mark is irradiated at the substantially central portion in the photographing area to be photographed with the desired width overlapping, the reference wood having no distortion is obtained. A program for causing a computer to function as an image processing unit that detects a deviation amount from a mark position and detects a distortion height that is a distortion in the height direction of wood from the detected deviation amount.

Images